quote:NASA's first shuttle mission since the Columbia accident will be delayed until July because of fears that ice could shake free from Discovery's external fuel tank, triggering another deadly disaster.

NASA halted launch preparations at launch pad 39B on Thursday. Discovery will be hauled back to the Vehicle Assembly Building to fix the 15-story fuel tank as early as next week, according to a NASA official familiar with the decision. NASA will announce the decision today.

The extra time also will allow NASA to deal with other technical problems that have cropped up recently at the pad.

"I don't think we're ready to fly yet," the official said. "Is it disappointing? Yes. But is it the right thing to do? Yes."

NASA plans two news events today, April 29, to update media representatives on the agency's Space Shuttle Return to Flight efforts and the STS-114 mission.

At 10:30 a.m. EDT, NASA Administrator Michael Griffin and Associate Administrator for Space Operations William Readdy will speak with reporters at Headquarters in Washington. The news conference will be carried live on NASA Television and www.nasa.gov. Questions from media representatives outside of Washington unfortunately cannot be supported.

At 11:30 a.m., Space Shuttle Program Manager Bill Parsons, Deputy Space Shuttle Program Manager Wayne Hale and International Space Station Program Manager Bill Gerstenmaier will talk to media about the status of preparations for Return to Flight. Reporters at NASA's Johnson Space Center in Houston and participating agency field centers will be able to ask questions during this news conference.

NASA TV is available on the Web and via satellite in the continental U.S. on AMC-6, Transponder 9C, C-Band, at 72 degrees west longitude. The frequency is 3880.0 MHz. Polarization is vertical, and audio is monaural at 6.80 MHz. It is available in Alaska and Hawaii on AMC-7, Transponder 18C, C-Band, at 137 degrees west longitude. The frequency is 4060.0 MHz. Polarization is vertical, and audio is monaural at 6.80 MHz.

quote:NASA announced on April 29 that Discovery's Return to Flight would move to the July launch window to allow for further safety analysis and perhaps the addition of a heater to the external tank to address icing issues. The decision was made April 28, after a series of reviews showed that further work was needed to address debris issues and some items that were discovered during work on the launch pad.

"We're going to return to flight, not rush to flight," said NASA Administrator Michael Griffin. "We're going to do it right."

ASCAN1984

When ever we are safew to fly we will fly. I have waited over two years. Iam sure i can wait another three months.

Robert Pearlman

From the NASA press conference held today from Johnson Space Center:

The vehicle (Discovery) will stay at the pad "for some time" to continue processing and tests and then at "some point in time" will be rolled back to the Vehicle Assembly Building to complete the needed work.

"We cannot fly until we have convinced ourselves it is safe to fly."

International Space Station partners were a "bit disappointed" in slip from first window but understood the reasons.

Extra water will be launched on the next Progress to allow for the slip.

Payload at the cape is in its canister and will stay packed up and ready to go. It can stay in its vertical configuration through September.

Testing shows that low density (slushy) ice and hard ice possess the same risk for damage. So more concern exists for the ice on the External Tank.

An ET LOX feed-line bellows heater is planned for installation to eliminate the ice in this area of concern (with the STS-121 tank receiving the modification first). Further testing is needed before a decision to install is made. This work cannot be done at the pad; it must be done inside the VAB but can be done with the orbiter attached.

The current Elektron (Russian air conditioner) failure on ISS will not impact a "safe haven" scenario.

No date yet on rollback of Discovery; will be determined on how much work can be done at the pad and the "fault tree" being mapped out; heater kit won't be available at the Cape until May 5.

As of now, Terminal Countdown Demonstration Test (TCDT) will proceed as planned next week.

Window opens July 13, ~3:45pm EDT.

Prior flights' ice hits on solid rocket booster cork and orbiter tile have led to a greater understanding of how ice separates from the LOX feed-line bellows area. Further testing includes a planned wind tunnel test accelerating ice to Mach 3.

Though Administrator Mike Griffin offered insight into the decision process, he did not "influence" this slip but agreed with the existing findings.

The next Soyuz launch may slip (with Russian cooperation) to allow for a larger September window for STS-121 (or STS-114, if it slips again).

STS-114 crew reaction to the delay as summarized by Soichi Noguchi: "Well, we got four days closer to launch then last time [in 2003]." The crew is encouraged that NASA is doing what it takes to launch safely. They look forward to using the extra time to further train and will take part in TCDT next week.

TPS damage (from the earlier fuel spill) may result in replacement or they may be cleaned/repaired.

Atlantis processing is going "very well". They are a "little behind, couple of days, maybe a week". Decision to slip was not based on Atlantis preparation.

[This message has been edited by Robert Pearlman (edited April 29, 2005).]

LT Scott Schneeweis

Band-aid fixes. The sheer complexity of the launch vehicle/fragility of the TPS design coupled with the (appropriate) level of post STS-107 convervatism introduced into the go/no-go decision tree will likely continue to further delay this and all subsequent shuttle launches. Better strategy to support more aggressive Soyuz/Progress resply runs, terminate Shuttle, recouping the funds to apply towards development of a more mature national space delivery platform.

One of the considerations for these launch windows is to have daylight all the way to ET sep, so they can film the whole ascent on the odd chanace another chunk of insulation falls. Theyre only going to the ISS, so they can do a visual inspection there...

Nomatter how much new safety margin is built in, If we lose another orbiter, the program is dead -- but the program ens in 2010 or 2011 anyway -- and the over engineering of the safety margin is going to massively limit the remaining number of flights. An ET redesign was fine, but just fly the dang thing with a perfectly reasonable 50:1 risk, or hang it up -- big delays to drop it to, what 80:1 when we're looking at maybe 25 flights left is just counterproductive.

spaceuk

When shuttle started flying the first few ET tanks were 'painted' white over the foam (STS-1,STS-2 etc).

The paint was discarded as a weight saver.

But,I wonder what effect the paint may have had on "retaining" the foam ?

PhillUK

RichieB16

Does anyone know how this will effect Thomas Reiter's mission to ISS. I would imagine that we will still fly on STS-121 (September?) and will simply lose a couple months on his mission but will finish with the current expedition and stay with the next.

STEVE SMITH

Phil, I'd wondered the same thing. In industrial intallations we have a cover over insulation such as thin wall aluminum or plastic jacket. Granted we don't need such a cover here to provide longevity, especially at the weight penalty.

However I like you wonder if some type of coating wouldn't give more cohesion for the liftoff.

A good question Phil.

Robert Pearlman

quote:Originally posted by Rodina:One of the considerations for these launch windows is to have daylight all the way to ET sep, so they can film the whole ascent on the odd chanace another chunk of insulation falls.

The visibility precautions are only applicable to the first two return to flight missions, STS-114 and STS-121 so they can insure the fixes they have implemented work. Later missions will have a wider choice of launch windows, including at night.

star61

Phil (space uk)

I actually sent an e-mail with just that question to the NASA office that requested ideas. I recieved a semi-technical response that indicated no cohesion benefit from the paint. I even suggested latex based paints, but no benefit would be apparent.

Phil

spaceheaded

Phill, Phil, and Steve,I too emailed NASA with that idea in the weeks following 107, but got no response. I wonder if they have comparison data on foam loss, STS1 & 2 vs all the rest. Maybe it wasn't even looked at early on.